Ubuntu's goal is to be secure "out-of-the box". By default, the user's programs run with low privileges and cannot corrupt the operating system or other user's files. For increased security, the sudo tool is used to assign temporary privileges for performing administrative tasks, which allows the root account to remain locked and helps prevent inexperienced users from inadvertently making catastrophic system changes or opening security holes.[21]PolicyKit is also being widely implemented into the desktop to further harden the system. Most network ports are closed by default to prevent hacking.[22] A built-in firewall allows end-users who install network servers to control access. A GUI (GUI for Uncomplicated Firewall) is available to configure it.[23] Ubuntu compiles its packages using GCC features such as PIE and buffer overflow protection to harden its software.[24] These extra features greatly increase security at the performance expense of 1% in 32 bit and 0.01% in 64 bit.[25]

Ubuntu is built on Debian's architecture and infrastructure, to provide Linux server, desktop, phone, tablet and TV operating systems.[27] Ubuntu releases updated versions predictably – every six months[11] – and each release receives free support for nine months (eighteen months prior to 13.04)[28] with security fixes, high-impact bug fixes and conservative, substantially beneficial low-risk bug fixes.[29] The first release was in October 2004.

It was decided that every fourth release, issued on a two-year basis, would receive long-term support (LTS).[11] Long-term support includes updates for new hardware, security patches and updates to the 'Ubuntu stack' (cloud computing infrastructure).[16] The first LTS releases were supported for three years on the desktop and five years on the server; since Ubuntu 12.04 LTS, desktop support for LTS releases was increased to five years as well.[30][31][32] LTS releases get regular point releases with support for new hardware and integration of all the updates published in that series to date.[33]

Ubuntu packages are based on packages from Debian's unstable branch: both distributions use Debian's debpackage format and package management tools (APT and Ubuntu Software Center). Debian and Ubuntu packages are not necessarily binary compatible with each other, however; packages may need to be rebuilt from source to be used in Ubuntu.[34] Many Ubuntu developers are also maintainers of key packages within Debian. Ubuntu cooperates with Debian by pushing changes back to Debian,[35] although there has been criticism that this does not happen often enough. Ian Murdock, the founder of Debian, has expressed concern about Ubuntu packages potentially diverging too far from Debian to remain compatible.[36] Before release, packages are imported from Debian Unstable continuously and merged with Ubuntu-specific modifications. A month before release, imports are frozen, and packagers then work to ensure that the frozen features interoperate well together.

Ubuntu is currently funded by Canonical Ltd. On 8 July 2005, Mark Shuttleworth and Canonical Ltd. announced the creation of the Ubuntu Foundation and provided an initial funding of US$10 million. The purpose of the foundation is to ensure the support and development for all future versions of Ubuntu. Mark Shuttleworth describes the foundation as an "emergency fund" (in case Canonical's involvement ends).[37]

On 12 March 2009, Ubuntu announced developer support for 3rd-party cloud management platforms, such as those used at Amazon EC2.[38]

Unity became the default GUI for Ubuntu Desktop (not included in 10.10).[39][40]

Ubuntu running on the Nexus S, a smartphone that ran Android prior to Ubuntu

The system requirements vary among Ubuntu products. For the Ubuntu desktop release 14.04, a PC with at least 768 MB of RAM and 5 GB of disk space is recommended.[41] For less powerful computers, there are other Ubuntu distributions such as Lubuntu and Xubuntu. As of version 12.04, Ubuntu supports the ARM architecture.[3][4][5][6] Ubuntu is also available on PowerPC,[3][42][43] and SPARC platforms,[citation needed] although these platforms are not officially supported.[44]

Live images are the typical way for users to assess and subsequently install Ubuntu. These can be downloaded as a disk image (.iso) and subsequently burnt to a DVD and booted, or run via UNetbootin directly from a USB drive (making, respectively, a live DVD or live USB medium). Running Ubuntu in this way is typically slower than running it from a hard drive, but does not alter the computer unless specifically instructed by the user. If the user chooses to boot the live image rather than execute an installer at boot time, there is still the option to then use an installer called Ubiquity to install Ubuntu once booted into the live environment.[45]Disk images of all current and past versions are available for download at the Ubuntu web site.[46] Various third-party programs such as remastersys and Reconstructor are available to create customized copies of the Ubuntu Live DVDs (or CDs). "Minimal CDs" are available (for server use) that fit on a CD.

Additionally, USB flash drive installations can be used to boot Ubuntu and Kubuntu in a way that allows permanent saving of user settings and portability of the USB-installed system between physical machines (however, the computers' BIOS must support booting from USB).[47] In newer versions of Ubuntu, the Ubuntu Live USB creator can be used to install Ubuntu on a USB drive (with or without a live CD or DVD). Creating a bootable USB drive with persistence is as simple as dragging a slider to determine how much space to reserve for persistence; for this, Ubuntu employs casper.[48][49]

The desktop edition can also be installed using the Netboot image (aka netbook tarball) which uses the debian-installer and allows certain specialist installations of Ubuntu: setting up automated deployments, upgrading from older installations without network access, LVM and/or RAID partitioning, installs on systems with less than about 256 MB of RAM (although low-memory systems may not be able to run a full desktop environment reasonably).[50]

Ubuntu divides most software into four domains to reflect differences in licensing and the degree of support available.[51] Some unsupported applications receive updates from community members, but not from Canonical Ltd.

Free software

Non-free software

Supported

Main

Restricted

Unsupported

Universe

Multiverse

Free software includes software that has met the Ubuntu licensing requirements,[51] which roughly correspond to the Debian Free Software Guidelines. Exceptions, however, include firmware and fonts, in the Main category, because although they are not allowed to be modified, their distribution is otherwise unencumbered.[citation needed]

Non-free software is usually unsupported (Multiverse), but some exceptions (Restricted) are made for important non-free software. Supported non-free software includes device drivers that can be used to run Ubuntu on some current hardware, such as binary-only graphics carddrivers. The level of support in the Restricted category is more limited than that of Main, because the developers may not have access to the source code. It is intended that Main and Restricted should contain all software needed for a complete desktop environment.[51] Alternative programs for the same tasks and programs for specialized applications are placed in the Universe and Multiverse categories.

In addition to the above, in which the software does not receive new features after an initial release, Ubuntu Backports is an officially recognized repository for backporting newer software from later versions of Ubuntu.[52] The repository is not comprehensive; it consists primarily of user-requested packages, which are approved if they meet quality guidelines. Backports receives no support at all from Canonical, and is entirely community-maintained.

The -updates repository provides stable release updates (SRU) of Ubuntu and are generally installed through update-manager. Each release is given its own -updates repository (e.g. intrepid-updates). The repository is supported by Canonical Ltd. for packages in main and restricted, and by the community for packages in universe and multiverse. All updates to the repository must meet certain requirements and go through the -proposed repository before being made available to the public.[53] Updates are scheduled to be available until the end of life for the release.

In addition to the -updates repository, the unstable -proposed repository contains uploads which must be confirmed before being copied into -updates. All updates must go through this process to ensure that the patch does truly fix the bug and there is no risk of regression.[54] Updates in -proposed are confirmed by either Canonical or members of the community.

Canonical's partner repository lets vendors of proprietary software deliver their products to Ubuntu users at no cost through the same familiar tools for installing and upgrading software.[55] The software in the partner repository is officially supported with security and other important updates by its respective vendors. Canonical supports the packaging of the software for Ubuntu[55][56][57] and provides guidance to vendors.[55] The partner repository is disabled by default and can be enabled by the user.[58] Some popular products distributed via the partner repository as of 28 April 2013[update] are Adobe Flash Player, Adobe Reader and Skype.

Additionally, third party application suites are available for purchase through Ubuntu Software Center,[60] including many high-quality games such as Braid and Oil Rush,[61] software for DVD playback and media codecs.

Each Ubuntu release has a version number that consists of the year and month number of the release.[68] For example, the first release was Ubuntu 4.10 as it was released on 20 October 2004. Version numbers for future versions are provisional; if the release is delayed the version number changes accordingly.

Ubuntu releases are also given alliterativecode names, using an adjective and an animal (e.g., "Trusty Tahr" and "Precise Pangolin"). With the exception of the first two releases, code names are in alphabetical order, allowing a quick determination of which release is newer. "We might skip a few letters, and we'll have to wrap eventually." says Mark Shuttleworth while describing the naming scheme.[69] Commonly, Ubuntu releases are referred to using only the adjective portion of the code name; for example, the 14.04 LTS release is commonly known as "Trusty".

Releases are timed to be approximately one month after GNOME releases (which in turn are about one month after releases of X.org). As a result, every Ubuntu release was introduced with an updated version of both GNOME and X. After each release, the Ubuntu Developer Summit (UDS) is held, at which the Ubuntu community sets the development direction for the next cycle.[70]

Upgrades between releases have to be done from one release to the next release (e.g. Ubuntu 13.10 to Ubuntu 14.04) or from one LTS release to the next LTS release (e.g. Ubuntu 12.04 LTS to Ubuntu 14.04 LTS).[71]

The variant officially recommended for most users, and officially supported by Canonical, is Ubuntu Desktop (formally named as Ubuntu Desktop Edition, and simply called Ubuntu), designed for desktop and laptop PCs using Unity Desktop interface (earlier versions used GNOME).[76] A number of other variants are distinguished simply by each featuring a different desktop environment: Ubuntu GNOME (with the GNOME desktop environment), Ubuntu MATE (with the MATE desktop environment), Kubuntu (with KDE Plasma Workspaces), Lubuntu (with LXDE), and Xubuntu (with Xfce). LXDE[77] and Xfce[78] are sometimes recommended for use with older PCs that may have less memory and processing power available.

Besides Ubuntu Desktop, there are several other official Ubuntu editions, which are created and maintained by Canonical and the Ubuntu community and receive full support from Canonical, its partners and the Community. They include the following:[79][80]

Ubuntu Business Desktop Remix, a release meant for business users that comes with special enterprise software including Adobe Flash, Canonical Landscape, OpenJDK 6 and VMware View, while removing social networking and file sharing applications, games and development/sysadmin tools.[81] The goal of the Business Desktop Remix is not to copy other enterprise-oriented distributions, such as Red Hat Enterprise Linux, but to make it, according to Mark Shuttleworth's blog, "easier for institutional users to evaluate Ubuntu Desktop for their specific needs."[82]

Ubuntu has a server edition that uses the same APT repositories as the Ubuntu Desktop Edition. The differences between them are the absence of an X Window environment in a default installation of the server edition (although one can easily be installed including Unity, GNOME, KDE or XFCE) and the installation process.[91] The server edition uses a screen mode character-based interface for the installation, instead of a graphical installation process.

Ubuntu Touch is an alternate version of Ubuntu developed for smartphones and tablets which was announced on 2 January 2013. Ubuntu Touch was Released To Manufacturing on 16 September 2014.[92] The first device to run it was the Galaxy Nexus.[93] A demo version for higher-end Ubuntu smartphones was shown that could run a full Ubuntu desktop when connected to a monitor and keyboard, which was to ship as Ubuntu for Android.[94] A concept for a smartphone running Ubuntu for Phones was published[when?] on Ubuntu's official channel on YouTube. The platform allows developing one app with two interfaces: a smartphone UI, and, when docked, a desktop UI.[95] Ubuntu for Tablets was previewed at 19 February 2013. According to the keynote video, an Ubuntu Phone will be able to connect to a tablet, which will then utilize a tablet interface; plugging a keyboard and mouse into the tablet will transform the phone into a desktop; and plugging a television monitor into the phone will bring up the Ubuntu TV interface.[96]

Ubuntu offers Ubuntu Cloud Images which are pre-installed disk images that have been customized by Ubuntu engineering to run on cloud-platforms such as Amazon EC2, OpenStack, Windows and LXC.[98] Ubuntu is also prevalent on VPS platforms such as DigitalOcean.[99]

Ubuntu 11.04 added support for OpenStack, with Eucalyptus to OpenStack migration tools added by Canonical in Ubuntu Server 11.10.[100][101]Ubuntu 11.10 added focus on OpenStack as the Ubuntu's preferred IaaS offering though Eucalyptus is also supported. Another major focus is Canonical Juju for provisioning, deploying, hosting, managing, and orchestrating enterprise data center infrastructure services, by, with, and for the Ubuntu Server.[102][103]

Because of a lack of registration, any number provided for Ubuntu usage can only be estimated.[104] In 2015, Canonical's Ubuntu Insights page stated "Ubuntu now has over 40 million desktop users and counting".[105]

W3Techs estimated in October 2013 that:

Ubuntu is used by 26.1% of all Linux websites, behind only Debian (on which Ubuntu is based), which is used by 32.7% of all Linux websites.[106]

Ubuntu is the most popular Linux distribution among the top 1000 sites and gains around 500 of the top 10 million websites per day.[107]

Ubuntu is used by 8.2% of all websites analyzed, growing from less than 7% in October 2012.[108]

W3Techs only analyses the top 10 million websites.[109] It considers Linux as a subcategory of Unix and estimated in the same month that 66.4% of the analyzed websites use Unix.[110]

According to thecloudmarket.com, Ubuntu is on at least 54% of the images it scanned on Amazon EC2.[111]

Wikimedia data (based on User agent) for September 2013 shows that Ubuntu generated the most page requests to Wikimedia among recognizable Linux distributions.[112][113]

The public sector has also adopted Ubuntu. As of January 2009[update], the Ministry of Education and Science of Republic of Macedonia deployed more than 180,000[114] Ubuntu-based classroom desktops, and has encouraged every student in the country to use Ubuntu-powered computer workstations;[115] the Spanish school system has 195,000 Ubuntu desktops.[114] The French police, having already started using open-source software in 2005 by replacing Microsoft Office with OpenOffice.org, decided to transition to Ubuntu from Windows XP after the release of Windows Vista in 2006.[116] By March 2009, the Gendarmerie Nationale had already switched 5000 workstations to Ubuntu.[116] Based on the success of that transition, it planned to switch 15,000 more over by the end of 2009 and to have switched all 90,000 workstations over by 2015 (GendBuntu project).[116] Lt. Colonel Guimard announced that the move was very easy and allowed for a 70% saving on the IT budget without having to reduce its capabilities.[116] In 2011, Ubuntu 10.04 was adopted by the Indian justice system.[117] The Government of Kerala adopted Ubuntu for the legislators in Kerala and the government schools of Kerala began to use customized IT@School Project Ubuntu 10.04 which contains specially created software for students. Earlier, Windows was used in the schools. Textbooks were also remade with Ubuntu syllabus and are currently used in schools.[118]

The city of Munich, Germany has forked Kubuntu 10.04 LTS and created LiMux for use on the city's computers.[119] After originally planning to migrate 12,000 desktop computer to LiMux, it was announced in December 2013 that the project had completed successfully with the migration of 14,800 out of 15,500 desktop computers.[120] In March 2012, the government of Iceland launched a project to get all public institutions using free and open-source software. Already several government agencies and schools have adopted Ubuntu. The government cited cost savings as a big factor for the decision, and also stated that open source software avoids vendor lock-in. A 12-month project was launched to migrate the biggest public institutions in Iceland to open-source, and help ease the migration for others.[121] Incumbent U.S. president Barack Obama's successful campaign for re-election in 2012 used Ubuntu in its IT department.[122] In August 2014, the city of Turin, Italy, announced the migration from Windows XP to Ubuntu for its 8,300 desktop computers used by the municipality, becoming the first city in Italy to adopt Ubuntu.[123][124]

Ubuntu was awarded the Reader Award for best Linux distribution at the 2005 LinuxWorld Conference and Expo in London,[125] received favorable reviews in online and print publications,[126][127] and has won InfoWorld's 2007 Bossie Award for Best Open Source Client OS.[128] In early 2008 PC World named Ubuntu the "best all-around Linux distribution available today", though it criticized the lack of an integrated desktop effects manager.[129] Although it is likely to be a prejudiced view, since Google promotes their own Linux-derived operating system called Android for mobile devices, Chris DiBona, the program manager for open-source software at Google, said “I think Ubuntu has captured people’s imaginations around the Linux desktop,” and “If there is a hope for the Linux desktop, it would be them”. As of January 2009[update], almost half of Google’s 20,000 employees used a slightly modified version of Ubuntu.[114]

In March 2013, Canonical announced that it had decided to develop Mir,[133] reversing an earlier plan to move to Wayland as the primary Ubuntu display server[134] and causing widespread objection from the open source desktop community.[135][136][137][138] X.Org contributor Daniel Stone opined: "I'm just irritated that this means more work for us, more work for upstream developers, more work for toolkits, more work for hardware vendors...."[139] In September 2013, an Intel developer removed XMir support from their video driver and wrote "We do not condone or support Canonical in the course of action they have chosen, and will not carry XMir patches upstream".[140][141][142]

In January 2014, the UK's authority for computer security, CESG, reported that Ubuntu 12.04 LTS was "the only operating system that passes as many as 9 out of 12 requirements without any significant risks".[143]

Ubuntu's developers acknowledged battery life problems from version 10.04[citation needed] and sought to solve the issues of power consumption in the 12.04 LTS release.[145] The 14.04 release improved the situation, but still lagged other operating systems in the battery life metric.[146]

One of the new features of Unity in Ubuntu 12.10 was the shopping lens – Amazon search results displayed in the Unity dash. It was alternately described as the "Amazon controversy",[147][148] "privacy fiasco"[149] and "spyware".[150]

As of October 2012[update], it sent (through a secure HTTPS connection) the user's queries from the home lens to productsearch.ubuntu.com,[151] which then polled Amazon.com to find relevant products; Amazon then sent product images directly to the user's computer through HTTP (this changed in September 2013). If the user clicked in one of these results and then bought something, Canonical got a small fraction of the sale.[152]

In 2012, many reviewers criticized it: as the home lens is the natural means to search for content on the local machine, reviewers were concerned about the disclosure of queries that were intended to be local, creating a privacy problem.[151] As the feature is active by default[151][152][153][154] (instead of opt-in), many users could be unaware of it.

Some users chose to turn it off or to remove the feature using a patch.[155] An April 2014 article by Scott Gilbertson stated that the online search components of Ubuntu could be turned off with a couple of clicks in version 14.04. The feature may be changed to opt-in in a future release.[146]

In an effort to reach out to users who are less technical, and to foster a sense of community around the distribution, Local Communities,[157] better known as "LoCos", have been established throughout the world. Originally, each country had one LoCo Team. However, in some areas, most notably the United States and Canada, each state or province may establish a team. A LoCo Council approves teams based upon their efforts to aid in either the development or the promotion of Ubuntu.

Ubuntu works closely with OEMs to jointly make Ubuntu available on a wide range of devices.[158] A number of vendors offer computers with Ubuntu pre-installed, including Dell,[159]Hasee,[160]Sharp Corporation,[161] Specifically, Dell offers the XPS 13 laptop, Developer Edition with Ubuntu pre-installed.[162] Together, Dell, Lenovo, HP, and ASUS offer over 200 desktop and close to 500 laptop PCs preloaded with Ubuntu. Certified OEM images are also available for Ubuntu Advantage customers.[158]System76,[163] WeWi[164] and Tesco[citation needed]. System76 PCs are sold exclusively with Ubuntu. Dell and System76 customers are able to choose between 30-day, three-month, and yearly Ubuntu support plans through Canonical.[165] Dell computers (running Ubuntu 10.04) include extra support for ATI Video Graphics, Dell Wireless, Fingerprint Readers, HDMI, Bluetooth, DVD playback (using LinDVD), and MP3/WMA/WMV.[166]Asus is also selling some Asus Eee PCs with Ubuntu pre-installed and announced that "many more" Eee PC models running Ubuntu for 2011.[167][168][169]Vodafone has made available a notebook for the South-African market called "Webbook".[170][171][172]

Dell sells computers (initially Inspiron 14R and 15R laptops) pre-loaded with Ubuntu in India and China, with 850 and 350 retail outlets respectively.[173][174] Starting in 2013, Alienware began offering its X51 model gaming desktop pre-installed with Ubuntu at a lower price than if it were pre-installed with Windows.[175]